It is a problem in the field of power conversion that a 50/60 Hz AC power source is typically used in switched mode inverters and converters to provide the input power. The resultant power converter must then deal with both the efficiency of the power conversion operation and the quality of the output voltage, due to the noise generated by converting the 50/60 Hz AC power in the power conversion operation.
In operation, after rectification of the input AC voltage, the power converter conventionally smoothes out the rectified DC sinusoid peaks by using large value electrolytic capacitors. This causes an enormous AC current inrush to the initially uncharged electrolytic capacitors when the power converter is first turned on. In addition, in high power applications, the power converters that use a 50/60 Hz AC power source must comply with regulatory requirements that specify high Power Factor (PF), low Total Harmonic Distortions (THD), and maximum Electromagnetic Interference (EMI) limits. Furthermore, power converter performance is primarily measured in terms of the circuit's ability to regulate power, ripple contents, long-term reliability, and conversion efficiency. Size, weight, and cost are also bottom line determining factors for commercialization of the device.
The power converters can use conventional boost circuit topology to provide high Power Factor, low Total Harmonic Distortion, and output DC power regulation. However, these are achieved in exchange for additional circuitry and power loss, which causes higher cost, increased device size, and in many instances low power conversion efficiency. In addition, high frequency noise is generated by power component switching actions within the power converter.
Therefore, it is difficult to satisfy these competing requirements to produce a power converter that is efficient, reliable, cost effective, and also maintains a constant output to the load without producing an unacceptable level of EMI.